How to Select the Right Batteries

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How to Select the Right Batteries

Millions of people around the world use batteries every day to power their lives. Few understand what batteries actually are or how they work. Every time someone uses a car, camera, cell phone, or remote control, the miracle of battery technology powers these items without the need to access an electrical outlet. Batteries free people from corded appliances, and let them be as mobile as they want without sacrificing modern conveniences.

Choosing batteries may seem to be just a matter of buying the right size, but there is much more to it than that. First, buyers need to know what their options are, so they can make better decisions, both financially and environmentally. Understanding what types of batteries are available helps buyers select the right batteries every time. Finally, learning about battery storage and handling rounds out a buyer's battery education.

A Brief History of Electricity

Many people believe that humanity's relationship with electricity began when Benjamin Franklin "discovered" electricity by flying a kite during a lightning storm, or when Alessandro Volta invented the battery. This could not be further from the truth. Although both of these men certainly made contributions to harnessing electrical power, observations of and experimentation with electrical activity began way before these men hit the scene.

Historical records show that crude batteries may have been used as early as 200 B.C. in the Middle East. An archaeologist found clay jars in Iraq that contained metal rods; scientists who recreated these jars and filled them with common acids (such as wine or vinegar) were able to create a charge. The originals are known as the "Baghdad batteries", and are believed to have played a role in religious ceremonies, healing, or metallurgy. As for electricity itself, human experiences with electric eels and other similarly equipped fishes predated Franklin by a few thousand years. Even several hundred years before Franklin’s time, the Arabs made a logical connection between charged animals and lightning, using their word for "lightning" in reference to a species of ray. Static electricity was observed by ancient cultures, as well.

However, despite these early discoveries and experimentations, real advancements in the study of electricity did not take place until the 17th and 18th Centuries. Then, during the 19th Century, men such as Franklin, Volta, Nikola Tesla, Thomas Edison, and others developed practical applications that literally changed the world.

Chemical Composition of Batteries

The electrical charge of a battery is determined by its chemical composition. Two batteries of the same size may differ in voltage if they have different chemical makeups. For example, a standard AA alkaline primary battery puts out a nominal voltage of 1.5 volts, whereas a rechargeable AA NiMH battery rates at 1.2 volts. Some of the most common types of batteries include the following:

A battery consists of two ends that function quite differently. The positive terminal is connected to a cathode, while the negative terminal is connected to an anode. The anode produces electrons, which move through a separator and are absorbed by the cathode. These reactions create the electrical energy required to power the device. They do not occur until the battery is connected to the load (appliance) and a complete circuit is created. At which time, electrons begin to flow.

Single-Use vs. Rechargeable Batteries

A consumer’s first choice when it comes to batteries is usually between single-use and rechargeable batteries. Regardless of the technology, all batteries are eventually drained of energy. However, the difference is that single-use batteries are immediately disposable, while rechargeable batteries have many more life cycles in them.

Single-Use Batteries

Batteries that can only be used once before they cease to function entirely are known as "primary" or single-use batteries. Once a single-use battery is dead, the consumer disposes of it and replaces it with a new, fresh battery.

Rechargeable Batteries

The green movement has increased the demand for secondary or rechargeable batteries, which, many people are surprised to discover, have been around since the modern battery's early days. Unlike single-use batteries, when rechargeable batteries die, the consumer places them into a battery charging unit, which is in turn plugged into an electrical outlet. Recharging is basically a reversal of the process by which the electrical energy was discharged in the first place. Electrons flow from the cathode end back to the anode. After a time, the batteries become fully recharged and can be used again.

If someone finds a household battery and is unsure of how much life it has left, a battery tester can be used to determine this. Testing devices are relatively inexpensive, and can be a good investment for households that go through large quantities of batteries. It may be economical for people to switch out single-use batteries from appliances that are top priority and must be 100 per cent dependable. By testing the life of the partially drained batteries, the user can determine whether or not they have enough charge for use in another, less important appliance. Similarly, rechargeable batteries should be checked periodically to see if they need "freshening up" with a brief recharge.

Battery Sizes

One of the largest batteries in the world was created in China. It is the size of a building, covering an area approximately the size of a rugby field. The largest battery most people deal with regularly is the car battery; the smallest is the hearing aid battery. Hearing aid batteries are referred to as "button cell" or "coin" batteries, because they are small, flat, and round. These kinds of batteries are also used in watches and other small electronic devices.

The following chart lists the shapes and approximate dimensions of the most common household batteries and some less popular sizes. The most common sizes are listed in bold font.

Battery Size





50 by 17 mm



50.5 by 14 mm



44.5 by 10.5 mm



42.5 by 8.3 mm



60 by 21.5 mm



50 by 26.2 mm



61.5 by 34.2 mm



91 by 33 mm


Cutoff square

48.5 by 35.6 by 9.18 mm



30.2 by 12 mm



48.5 by 26.5 by 17.5 mm


Cuboid or box

115 by 68.2 by 68.2 mm

The chart above is by no means complete; there are myriad other less common batteries still in demand, and the list of button batteries alone is quite lengthy. The dimensions listed here are approximations, since they can vary by as much as a millimetre depending on the manufacturer. Dimensions come in handy for buyers who have an appliance that requires batteries but who have no old batteries, product placard, or literature to refer to for sizing. Users can measure the battery compartment and use the measurements to approximate the size of the batteries needed.

Other Battery Sizes

Most button batteries are designated by a series of letters and numbers, usually "CR" for lithium, "SR" for silver oxide, or "LR" for alkaline, followed by three to five digits.

Brands of Batteries

Generic batteries are readily available, although some buyers prefer to stick with name brands. The first battery was produced in 1898 by the company that later became Eveready, which makes Energizer batteries. This does not necessarily make this brand the best; plenty of other well-known battery manufacturers exist today, including Duracell, GP Batteries, Panasonic, Rayovac, and Renata. No-name alkaline batteries are among the least expensive available; however, consumers should consider that they likely have a short functional life and may not be very economical over the long run.

Battery Expiry Dates

Like food, medicine, and some cosmetics, batteries have a limited shelf life. Always check the package for the dates before purchasing batteries. In stores that do not sell a lot of batteries, items may have been sitting for quite some time before purchase. They may be nearing the point of expiry or already expired. Shelf life depends on the battery's chemical makeup. Some types, such as alkaline, last longer on the shelf but not as long during use. Other batteries have a shorter shelf life, but the fact that they are rechargeable makes them an ideal choice for appliances that receive constant use.

Proper Battery Disposal

When batteries finally die, many people throw them in with the regular household or office rubbish, but this is not the correct way to handle them. Batteries are considered hazardous waste, as many of the metals they contain are toxic. Should they leach out into the ground or be carried into the air through smoke when the batteries incinerated, such contaminants can damage the environment. Consumers should check the regulations for their local area; batteries should be recycled, either by taking them to a retail store that offers a drop-off, or to a landfill and hazardous waste disposal centre if a curbside recycling programme is not available. For convenience’s sake as well as earth consciousness, people who use a lot of batteries are better off choosing rechargeable models to avoid making frequent trips to dispose of dead batteries properly.

Where to Find Batteries

Batteries are an everyday part of society, and they are inexpensive enough that they are sold just about everywhere. Even the smallest petrol stations and convenience stores usually offer a few sizes of batteries. Other sources include chemists, grocery stores, hardware stores, home improvement stores, discount stores, flea markets, and closeout and bargain stores.

How to Buy Batteries on eBay

You can browse through thousands of batteries on eBay. How you choose to do this depends on your goals. If your intention is to look at batteries only, you may wish to do a keyword search from the homepage. Simply type "batteries" into the Search field, then click on Search or press Enter. The results you get will be in many categories. You can browse through all of them, or select a category that best meets your needs. If you already have a clear idea of what type of battery you want, your keyword search can be more specific; for example, you might type in "used lantern battery" or "zinc D batteries".

Another way to find batteries is to navigate through eBay’s organised categories. General household batteries are in one section, while batteries for specific items, such as cars, cameras, and phones, are usually listed in the section where those products are sold. This type of search is helpful if you want to look at the items themselves (such as new cameras) in addition to the batteries that go with them.


Batteries are an essential part of modern living. They power the tools and appliances that make daily tasks easier, faster, and more convenient. Batteries must be reliable, so that the items they power are ready for use at a moment’s notice. Not all batteries are created equal, so informed battery shopping involves more than knowing the right size.

The chemical reaction in a battery is what generates the electrical energy that powers a tool or toy. These reactions are created by different combinations of metals and chemical electrolytes; each chemical combination has benefits and drawbacks. Some provide a stronger charge, last longer on the shelf, or last longer when used in a device. Batteries are designated by their chemical makeup as well as their size. Primary batteries can be used only one time before disposal, whereas secondary batteries can be recharged up to 100 times or more before finally dying.

Consumers should know which chemistry suits their needs, whether they want primary or secondary batteries, what size they want, and what brand they prefer (if any). By arming themselves with this knowledge and being wary of expiry dates, battery buyers can select the right batteries for every situation.

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